1. Field of the Invention
The invention relates to a device for electrically adjusting a vehicle seat, with articulated constructions arranged on different sides of the vehicle seat, and with at least one electric motor with a gear mechanism coupled thereto for moving the articulated constructions, and with at least one mechanism for locking the articulated constructions.
2. Description of the Related Art
An electric motor with a gear mechanism unit coupled thereto customarily is provided for electrically adjusting articulated constructions arranged on the right and left side of the vehicle seat. The articulated constructions are moved by the gear mechanism unit to adjust the vehicle seat with regard to the height adjustment of the vehicle seat, the inclination adjustment of a seat cushion of the vehicle seat or the inclination position of a backrest of the vehicle seat. The electric motor with a gear mechanism unit coupled thereto adjust the articulated construction on the one side of the vehicle seat. The electric adjustment unit also forms a lock for the articulated construction on the corresponding side of the vehicle seat when the electric adjustment unit is in the inoperative state to keep the vehicle seat securely in its position. The articulated construction on the other side of the vehicle seat also has to be locked to ensure secure locking of the vehicle seat even in the event of a crash and the high forces occurring in the process. It is known for this purpose to use a force transmission tube that couples the left and the right articulated construction to each other and thereby transfers the locking force to the side without the electric adjustment unit. The force transmission tube is relatively heavy and also is flexible. Therefore the force transmission tube leads to an asymmetrical positioning of the vehicle seat due to the one-sided locking in the event of a crash.
DE 199 11 786 C2, JP 2008 024014 A and EP 0 245 650 A2 each describe an inertia drive for a crash locking of an adjustment device of a motor vehicle seat.
U.S. Pat. No. 6,902,234 B2, U.S. Pat. No. 4,040,591, GB 2 065 464 A and WO 99/05000 all relate to various embodiments of mechanical crash locks for adjustment devices of vehicle seats.
DE 199 53 630 C5, DE 101 37 298 C1, DE 103 06 827 B4, DE 103 06 828 B4 and EP 1 121 263 B1 each relate to a crash lock with the use of an additional load path in the case of a vehicle seat.
It is the object of the present invention to develop a device of the type described that ensures a precise adjustment of the vehicle seat and secure locking of the vehicle seat in the event of a crash.